Demonstrating Cryptosporidium removal using spore monitoring at lime-softening plants

Utility managers can use this article as an example of how aerobic spore monitoring can be used to demonstrate potential for Cryptosporidium removal at their own facilities. The authors discuss the Cryptosporidium removal potential in full-scale treatment processes using full-scale aerobic spore monitoring. Other utilities can use similar aerobic spore monitoring data to evaluate the potential of their treatment processes to remove Cryptosporidium, Giardia, and other microorganisms of public health concern. However, although raw water concentrations at participating utilities were higher than would be found at most places in the United States, the participating utilities could have benefited by using lower detection limits for filtered water samples. Other US utilities with lower raw water spore concentrations may have facilities capable of achieving 3.0-log or greater removal of spores and Cryptosporidium, but these facilities may not be able to mathematically demonstrate this capability unless they develop methods to achieve lower detection limits in filtered water samples.